1993 Volume 39 Issue 2 Pages 189-200
To evaluate the changes in zinc and copper concentrations in breast milk and maternal blood during lactation, milk and blood samples were obtained from 80 lactating women during the period be-tween 2 and 201 days of lactation. Zinc and copper concentrations were measured by atomic absorption spectrophotometry. Breast milk zinc and copper concentrations markedly decreased during the first few weeks of lactation and gradually declined for the remaining period. Mean values of milk zinc and copper levels were 1.76 and 0.29g/ml, respectively, be-tween 15 and 84 days after parturition and were 0.76 and 0.19μg/ml between 85 and 201 days of lactation. Calculated daily intakes of these minerals for infants from breast milk were markedly lower than those of U5 Recommended Dietary Allowances. Plasma zinc levels of lactating mothers increased as lactation progressed, whereas erythrocyte zinc and plasma copper concentrations decreased. Plasma zinc and copper and erythrocyte zinc values returned to normal approximately three months after parturition.
